I am not that familiar with this particular model, others members on here will be, but it may be worth checking the L/O Transistor has not gone short, before getting too involved.
That out line of red, blue and green may be just the H-Stat needing adjustment or even a poor connection, has it arced over ?. (i am assuming its got a H Stat)
, as I say not that familiar with this model.
Ken G6HZG.